Portable power wrench

ABSTRACT

A portable power wrench consisting of a first and a second pipe holder, and a hydraulic cylinder for turning the two holder relative to each other. The first holder holds a first pipe and swingably holds the hydraulic cylinder. The second holder is swingably connected to a piston rod of the cylinder and holds a second pipe threadedly engaging the first pipe in such a manner that, upon forward actuation of the hydraulic cylinder, the second pipe is turned, but when the piston rod is moved reversely, the second holder slides on the second pipe without turning the latter.

United States Patent I [I I1 3,880,024

Asada Apr. 29, 1975 PORTABLE POWER WRENCH 2.871.743 2/l959 Kelleyill/57.34

' 5 E 5 .3 [75] Inventor: Suekichi Asada, Nagoya. Japan 67 7 6H9)Kuchncr 7 4 Assignee? Kabushiki Tokai Tekkosha- Primary Bramirwr-JamcsL. Jones. Jr.

Nagoya. Japan [22] Filed: Jan. 9. 1974 [57] ABSTRACT [21] Appl. No.:431.973

A portable power wrench consisting of a first and a reign ApplicationPriority Data second pipe holder and a hydraulic cylinder for turn- July30. I973 Japan ..4s-ss7z9 ing the two holder relative to each er' he fist holder holds a first pipe and swingably holds the hy- [52] U.S. Cl.81/5134; 81/5739; 31/65 draulic cylinder. The second holder is swingablycon- [5| Int. Cl B25b r3150; B25!) 13/52 nected to a piston rod of theylind r and holds a sec- [58] Field of Search 81/5734. 57.36 57.39. 0ndp p threudedly g g g the first p p n such a 31 5 manner that, uponforward actuation of the hydraulic cylinder, the second pipe is turnedbut when the pis- [56] References Cit d ton rod is moved reversely, thesecond holder slides UNITED STATES PATENTS on the second pipe withoutturning the latter.

568.697 9/1896 Picket! 4. til/ 2.546.224 3/l95l Johunscn 81157.34 4Chin's 6 Drawing Figures 2.737.839 3/1956 Page! 81157.34

PAIEmEnmzsiis SHEET 10? 4 SHEET 3 0F 4 8 4 3Q 3w -II.- w I4 .D 7 w a w 3M O 5 s a WNW 4 n J/ 2 A H 5 my 2 O an IV 3 5 5 a /r Q 3 n7 3 Omemcnmzms 80,024

SHEET 0F 4 Fig-6 Fig.5

PORTABLE POWER WRENCH BACKGROUND OF THE INVENTION l. Field of theInvention This invention relates to a portable power wrench. and moreparticularly to a power wrench which hydraulically tightens the threadedjoint of two pipes so as to improve the efficiency of the wrench forsuch tightening work.

2. Description of the Prior Art Conventional pipe wrenches are manuallyoperated. Thus, when pipe joints include comparatively large diameterpipes or are located in relatively inaccessible spaces, such as near theceiling of a room, it is difficult and cumbersome to manipulate theconventional manual wrenches. Accordingly, the pipe connecting work bymeans of conventional wrenches is sometimes inefficient.

Therefore, an object of the present invention is to mitigate theaforesaid difficulty of the conventional wrench by providing ahydraulically operable power wrench of portable type.

SUMMARY OF THE INVENTION According to the present invention, there isprovided a portable power wrench which uses a hydraulic cylinder forthrcadedly connecting two pipes of comparatively large diameters witheach other or a pipe with an elbow or the like. The wrench of theinvention comprises a first and a second pipe holding means and ahydraulic cylinder means. The first holding means includes a bracket orbody, a holding portion formed integrally with the body, so as toselectively hold a first pipe member to be joined, and a shaft securedto the body so as to extend parallel to the longitudinal axis of thefirst pipe member. The hydraulic cylinder is slidably carried by saidshaft so as to be swingable about the shaft. The second holding meansincludes a swingable bar having one end pivotally connected to the freeend of a piston rod of the hydraulic cylinder, and a pipe-holdingportion provided at the opposite end of the swingable bar so as toselectively hold a second pipe member to be threadedly joined to thefirst pipe member. Said second holding means tightly holds the secondpipe member when the piston rod of the hydraulic cylinder is extendedfrom the cylinder, so as to turn the second pipe member in response tothe actuation of the hydraulic cylinder, but the second holding meansslides on the surface of the second pipe member when the piston rodreverses or is retracted into the hydraulic cylinder. Thus. uponrepeated actuations of the hydraulic cylinder, the first and second pipemembers are threadedly joined. To cope with the varied spacing betweenthe first and second holding means, the hydraulic cylinder may slide onthe shaft of the first holding means.

The first and second pipe members need not always be straight pipes. Forinstance, one of them can be an elbow connector.

With the power wrench of the aforesaid construction, the efficiency ofthe pipe connecting work can be greatly improved. Especially. when thework is to be carried out in a limited space. the operator can be re-Iieved from complicated and cumbersome manipulation in such narrowworkable space. Furthermore. the entire power wrench can be made in aportable fashion, so that it is very easy to handle.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a side view ofa power wrench,according to the present invention;

FIG. 2 is a view taken on IIII of FIG. 1, with a part thereof cutaway;

FIG. 3 is a partially cutaway view, taken on line III III of FIG. 1;

FIG. 4 is an enlarged view ofa swingable part of the power wrench;

FIG. 5 is a side view of a swingable rod of the power wrench, and

FIG. 6 is a sectional view taken along the line Vl--Vl of FIG. 5.

Like parts are designated by like numerals and symbols throughout thedifferent figures of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, a portablepower wrench according to the present invention comprises a firstholding means A carrying a hydraulic cylinder and a second holding meansB connected to a piston rod of the hydraulic cylinder. FIGS. 2 and 3illustrate details of the two holding means.

The first holding means A includes a bracket or body I having a headportion 2. In the head portion 2 there is bored a cylindrical hold I0 soas to receive a stud 22 therein to be described hereinafter. A pair ofviceholders 3 are integrally formed with the body I, and a vice-piece IIis replaceably secured to each of the viceholders 3. A hook 4 is formedat the right-hand side portion of the lower end of the body I, as seenin FIG. 2, by bifurcating the edge thereof. A hole 5 is bored throughthe left-hand end portion of the body I, as seen in FIG. 2, so as toreceive therein a chain-holding bolt 20 to be described hereinafter. Apair of lugs 8 are inte grally formed with the body I, so as to faceeach other across the hole 5. The lower portion 6 of the hole 5, as seenin FIG. 2, has a rectangular cross section or at least one planarsurface, and the upper portion 7 of the hole 5 is so tapered as toenlarge the hole diameter as the hole extends upwardly. A nut 12threadedly carrying the bolt 20 is fitted in the tapered upper portion 7of the hole 5. The nut 12 has an annular groove I4. so that the bolt 20can be rotatably carried by a pair of pins 9 secured to the lugs 8.Lower end I3 of the nut 12 is so tapered as to fit in the tapered upperend portion of the hole 5.

The vice pieces 11 are mounted on the body I in such a manner thatpipe-engaging surfaces of the vice pieces 11 substantially face towardthe longitudinal axis of a first pipe member a to be joined, as shown inFIG. 2. The nut I2 is manually rotatable by a handle 15, as shown byarrow I6. The handle 15 can be detachably mounted on the nut 12.

A pipe-holding chain l8 has one end connected to the chain-holding bolt20. After being extended around the pipe member a, a suitable portion ofthe chain 18 is fastened to the hook 4 of the body I by a chain pin I9.The chain-holding bolt 20 has one or more flattened surface portions 21,so that the bolt 20 would not rotate in the rectangular lower portion ofthe hole 5 of the body I by engagement of the flattened portions ZI ofthe bolt 20 with flat surfaces of that portion of the hole 5. A coilspring 17 is inserted between the top end of the bolt 20 and the nut 12,as shown in FIG. 2. After the chain I8 is placed around the pipe membera by fastening a suitable chain pin [9 to the hook 4. the handle I ismounted on the nut 12. and the nut 12 is rotated by the handle 15 so asto tighten the chain 18. Thus. the chain 18 cooperates with the vicepieces I] and securely holds the pipe member u.

The stud 22 fitted in the cylindrical hole III is fastened to the body Iby a screw 26. The top portion 23 of the stud 22 holds a shaft 24extending parallel to the longitudinal or axial direction of the pipemember a to be joined. which shaft 24 is secured to the stud by a screw25. A hydraulic cylinder 27 is slid-ably mounted on the shaft 24. sothat the cylinder 27 can swing about the shaft 24. as can be seen fromFIG. 3. The hydraulic cylinder 27 carries a piston rod 28 which ishydraulically actuatable. so as to reciprocate in a plane perpendicularto the longitudinal axis of the shaft 24.

Referring to FIGS. 3 to 6. the second holding means B includes aswingable bar 30 having one end pivot-ably connected to the free end ofthe piston rod 28 by a connector pin 29. The opposite end of theswingable bar 30 has a serration 32 formed along an imaginary arcuatesurface 32a whose center of curvature 31 is offset from the position ofthe connector pin 29. as shown in FIG. 4. The shape ofthe serration 32is such that. when the swingable bar 30 is actuated by extension of thepiston rod 28 of the hydraulic cylinder 27, the serration 32 operatinglyengages the peripheral surface of the pipe member b. but when the pistonrod 28 moves reversely into the hydraulic cylinder 27. the serration 32does not provide any substantial friction with the peripheral surface ofthe pipe member b.

The lower end of the swingable bar 30 has a hook 33 which receives achain pin 49 of a pipe-holding chain 48. as seen in FIG. 4. A pair ofbrackets 34 are integrally formed with the swingable bar 30 at anintermediate portion thereof. so as to receive a bent bar 37 which ispivotally connected to the brackets by a pin 35. The bent bar 37 servesto hold an end member 43 secured to one end of the pipe-holding chain48. by forming a part of the chain connector unit 36. The bent bar 37has a leg 38. which is engageable with a linear end portion 51 of a coilspring 50 located in a seating recess 52 of the swingable bar 30. Ahollow cylindrical portion 39 is integrally formed with the lowerportion of the bent bar 37. as seen in FIGS. 5 and 6. The cylindricalportion 39 has a vacant space 40 defined therein so as to receive theend member 43 of the chain 48. The cylindrical wall of the hollow space40 has a pair of aligned slots 41, through which a pin 45 secured to theend member 43 penetrates. Opposite ends of the pin 45 are secured to aring 46 which is slidably fitted on the outer peripheral surface of thecylindrical portion 39. The lower portion 42 of the outer surface of thecylindrical portion 39 is threaded. so as to threadedly receive a nut47. as seen in FIGS. 5 and 6. The top edge ofthe nut 47 engages the ring46. so that the position of the ring 46 and the end member 43. relativeto the bent bar 37 can be adjusted by turning the nut 47 engaging thethreaded portion 42 of the bent bar 37.

The lower end of the end member 43 is pivotally connected to the chain48 by a chain pin 49 through a U- shaped connector 44. as shown in FIGS.4 to 6. The U shaped connector 44 has arcuate edge surfaces 441:.

In operation. the pipe member a and b are aligned by engaging a part ofthe threaded portions thereof. as shown in FIG. I. The pipe-holdingchain 18 of the first holding means A is released from the hook 4. andthe vice-pieces II are placed respectively in a proper position on theperipheral surface of the first pipe member a. The chain [8 is woundaround the pipe member a. and it is looped by connecting a suitable partof the chain 18 to the hook 4 of the body 1 by a chain pin 9. The nut 12is turned by the handle 15 so as to move the bolt 20 away from the pipemember a for tightening the looped chain 8 against the first pipe membera. Similarly. the chain 48 of the second holding means B is freed fromthe hook 23 of the swingable bar 30, and it is wound around the secondpipe member b and looped by connecting a suitable portion of the chainback to the hook 33 by a chain pin 49. The not 47 is turned in such amanner that the end member 43 of the chain 48 is moved away from thepipe member b. Thus, the chain 48 is tightened against the peripheralsurface of the second pipe member b. while causing the serration 32 ofthe swingable bar 30 and the arcuate surface 44a of the connector 44 toengage the peripheral surface of the second pipe member b.

If the hydraulic cylinder 27 is actuated to extend the piston rod 28from the cylinder. under such conditions. the swingable bar 30 is turnedabout the longitudinal central axis of the aligned pipe members a andI). while the hydraulic cylinder 27 itself is slightly swayed about theshaft 24. At this moment, if the first holding means A is heldstationary. for instance by connecting the bracket or the body 1 to astationary member (not shown). the turning of the swingable bar 30results in a rotation of the second pipe member b in a direction. asshown by arrow 55 in FIGS. 3 and 4. The coil spring 50 provides a kindof buffering action in the pipe turning operation by the swingable bar30. and the serration 32 assists in transmitting the turning movement ofthe bar 30 to the pipe member b. Thus. the second pipe member b isturned relative to the first pipe member a. for completing the threadedconnection of the two pipe members.

After being fully extended the piston rod 28 may be retracted to to thecylinder 27 by suitable hydraulic action, the operating engagement ofthe serration 32 with the peripheral surface of the second pipe member bbeing released. Thus, the reverse movement ofthe piston rod 38, i.e..the movement toward the hydraulic cylinder 37. will cause the bar 30 toswing back. but the chain 48 slides along the peripheral surface of thepipe member b without turning the pipe member b. because the frictionbetween the two pipe members a and b at the threaded portions thereof islarge enough to allow the sliding reverse movement of the serration 32and the chain 48 on the peripheral surface of the second pipe member b.

Once the piston rod 28 is fully retracted into the hy draulic cylinder27. the rod 28 will be again pushed outwardly relative to the cylinder27. As a result. the bar 30 swings so to cause the serration 32 tooperatively engage the peripheral surface of the second pipe member I:and to turn the pipe member bin the direction of the arrow 55. asdescribed above. Thus. the threaded engagement between the pipe membersa and b can be fully tightened by repeated actions of the hydrauliccylinder 27 causing reciprocation of the piston rod 28.

It may be noted here that the second pipe member b will axially movetoward the first pipe member a in response to the aforesaid rotation ofthe former. due to the threaded engagement therebetween. Such movementof the two pipe members in the axial direction thereof will be absorbedduring the sliding reverse movement of the chain 48 of the secondpipe-holding means B and by sliding of the hydraulic cylinder 27 on theshaft 24.

It is apparent to those skilled in the art that the power wrench of thepresent invention can be used to cause the second pipe member I: torotate in a direction opposite the arrow 55, eg, for releasing thethreaded connection of the second pipe member h to the first pipe membera. For instance. the first holding means A may be mounted and tightenedon the second pipe member 11 and kept stationary by a suitable means(not shown). and the second holding means B may be operatively mountedon the first pipe member a. Then. the actuation of the power wrench willresult in the disengagement of the threaded connection between the twopipe members a and b.

I claim:

1. A portable power wrench. comprising a first holding means including abody having a head portion and vice holders integrally formed with thehead portion. vice pieces detachably secured to the vice holders tosubstantially immovably hold a first pipe member relative to the body.said head portion being provided with a hole. a stud secured in saidhole. a shaft received by said stud. said first pipe member being heldby said holding means in such a manner that the longitudinal axialcenter line of the first pipe member extends parallel to said shaft. ahydraulic cylinder slidably mounted on said shaft and swingable aboutsaid shaft. said bydraulic cylinder having a piston rod which isreciprocably movable in a plane perpendicular to said shaft; and asecond holding means including a swingable bar pivotally connected tosaid piston rod at one end thereof. a serration formed at the oppositeend of the swingable bar along an arc whose center of curvature isoffset from said end of the swingable bar connected to the piston rod.and means for holding a second pipe member while causing said serrationto engage the peripheral surface of the second pipe member. said secondpipe member being axially aligned with said first pipe member when thetwo pipe members are held by said first and second holding means.respectively.

2. A wrench according to claim I. wherein said first holding meansfurther includes a chain cooperating with said vice holders. and saidbody has a chain-endreceiving hole bored at one end of the vice holdersand a hook formed at the opposite end of the vice holders. said chainhaving an end member with a least one planar surface which end member isfitted in said chainend-receiving hole of the body. saidchain-endreceiving hole having at least one planar surface engageablewith said planar surface of the end member. said body having a chain endholding means holding said chain end member in said chain-end-receivinghole and a spring inserted between the chain end member and said chainend holding means. said chain including a plurality of chain pins eachof which is adapted to be selectively engaged with said hook of thebody.

3. A wrench according to claim 1 wherein said piston rod of thehydraulic cylinder is pivotally connected to said swing-able bar by aconnector pin.

4. A wrench according claim 1. wherein said means for holding saidsecond pipe member in said second holding means includes a chain havingan end member connected to one end thereof. said swingable bar of saidsecond holding means having a chain holding unit pivotally connected toan intermediate portion thereof. said chain holding unit adjustablyholding said chain end member. said swingable bar having a hookintegrally formed therewith at a position opposite to said chain holdingunit. said chain having a plurality of chain pins each of which isadapted to be selectively engaged with said hook of the swingable bar.

l =t= l

1. A portable power wrench, comprising a first holding means including abody having a head portion and vice holders integrally formed with thehead portion, vice pieces detachably secured to the vice holdErs tosubstantially immovably hold a first pipe member relative to the body,said head portion being provided with a hole, a stud secured in saidhole, a shaft received by said stud, said first pipe member being heldby said holding means in such a manner that the longitudinal axialcenter line of the first pipe member extends parallel to said shaft, ahydraulic cylinder slidably mounted on said shaft and swingable aboutsaid shaft, said hydraulic cylinder having a piston rod which isreciprocably movable in a plane perpendicular to said shaft; and asecond holding means including a swingable bar pivotally connected tosaid piston rod at one end thereof, a serration formed at the oppositeend of the swingable bar along an arc whose center of curvature isoffset from said end of the swingable bar connected to the piston rod,and means for holding a second pipe member while causing said serrationto engage the peripheral surface of the second pipe member, said secondpipe member being axially aligned with said first pipe member when thetwo pipe members are held by said first and second holding means,respectively.
 2. A wrench according to claim 1, wherein said firstholding means further includes a chain cooperating with said viceholders, and said body has a chain-end-receiving hole bored at one endof the vice holders and a hook formed at the opposite end of the viceholders, said chain having an end member with a least one planar surfacewhich end member is fitted in said chain-end-receiving hole of the body,said chain-end-receiving hole having at least one planar surfaceengageable with said planar surface of the end member, said body havinga chain end holding means holding said chain end member in saidchain-end-receiving hole and a spring inserted between the chain endmember and said chain end holding means, said chain including aplurality of chain pins each of which is adapted to be selectivelyengaged with said hook of the body.
 3. A wrench according to claim 1wherein said piston rod of the hydraulic cylinder is pivotally connectedto said swingable bar by a connector pin.
 4. A wrench according claim 1,wherein said means for holding said second pipe member in said secondholding means includes a chain having an end member connected to one endthereof, said swingable bar of said second holding means having a chainholding unit pivotally connected to an intermediate portion thereof,said chain holding unit adjustably holding said chain end member, saidswingable bar having a hook integrally formed therewith at a positionopposite to said chain holding unit, said chain having a plurality ofchain pins each of which is adapted to be selectively engaged with saidhook of the swingable bar.